Bacterial pathogens must adapt to available nutrients in their host, so they have linked metabolism with virulence. We want to understand the mechanisms by which G+ pathogens regulate virulence in response to available carbohydrates. GAS is a significant pathogen causing an array of diseases and depends upon sugar uptake for host survival. The PTS is a conserved phosphorelay coupling sugar transport and signal transduction.The Mga regulator influences both virulence and sugar utilization genes in GAS. We've shown that Mga is phosphorylated within PTS regulatory domains (PRD) that alter Mga activity and virulence in GAS. Furthermore, homologous regulators are found in GAS and other pathogenic streptococci. We propose that Mga represents a family of PRD-containing virulence regulators (PCVR) that allows sugar metabolism to influence the disease process. This renewal will continue our studies on Mga as the archetype PCVR, while expanding our scope to include potential PCVR from pathogenic streptococci. We propose the following aims: 1) Further define functional domains of Mga and establish their conservation in other PCVRs from pathogenic streptococci; 2) Delineate the role of PTS components and sugars for signaling through Mga and potentially other RALPs in GAS; 3) Map the genome-wide genetic interactions of Mga in GAS using Tn-seq; 4) Examine the impact of PTS signaling on Mga and potentially RALPs during GAS infection. Advancing our understanding of PCVRs has potential for broad impact in the field of G+ bacterial pathogenesis and will hopefully lead to novel strategies to treat severe infections caused by these pathogens. PUBLIC HEALTH RELEVANCE: Bacterial pathogens must adapt to available nutrients in their host, so they have linked metabolism with virulence. The Mga virulence regulator of the group A streptococcus (GAS) represents a family of PRD- containing virulence regulators (PCVR) that allows sugar metabolism to influence the disease process. This renewal will continue our studies on Mga as the archetype PCVR, while expanding our scope to include potential PCVR from pathogenic streptococci.